Mission control erupted in cheers as officials exchanged hugs and handshakes after tense minutes of waiting.

"How sweet it is," retiring NASA Administrator Dan Goldin said during a late night news conference at the Jet Propulsion Laboratory. "It embodies the true American spirit that we could win after being knocked down a few times."

The spacecraft will take until late January to settle into a final, circular mapping orbit 200 miles (400 kilometers) above the planet.

"There's still a long ways to go. This was necessary though not sufficient to get the mission going," said Charles Whetsel, chief engineer of the Mars exploration program. "You've got to make it through this round before you get to play in the World Series. This is winning the pennant."

Odyssey dove over Mars' north pole and dipped behind the planet after the burn began, leaving mission team members waiting anxiously. About 20 minutes later the probe reappeared and transmitted a signal to Earth across 80 million miles (149 million kilometers) of space.

Scientists did not expect to know for up to three hours the exact orbital path the boxy spacecraft was traveling around Mars.

The Mars Odyssey, which reached Mars after a six-month, 250-million-mile (460-million-kilometer) journey from Earth, is the first mission to the planet since two NASA failures in 1999. For the space agency, the project represented a shot at redemption.

"It's great. It's wonderful. We're back at Mars," said Daniel McCleese, chief scientist of the JPL Mars program. "The orbit looks even better than the predictions. It's really good."